Bottom Line:
The lesion was considered inoperable due to the poor general condition of the patient.PPL is a rare disease that accounts for 0.45% of all pulmonary malignant tumors and is difficult to diagnose in inoperable cases.Therefore, patients with PPL who do not undergo surgery can be misdiagnosed and consequently treated inappropriately.

The current study presents a case of primary pulmonary lymphoma (PPL) mimicking refractory lung abscess that was diagnosed at autopsy. An 80-year-old male with clinically inapparent aspiration presented with a large cavitated mass and pleural effusion. A lung abscess and empyema was diagnosed, therefore, antibiotics were administered and the pleural effusion was drained. Various examinations, including a biopsy, yielded no specific diagnosis. The lesion was considered inoperable due to the poor general condition of the patient. Subsequently, the mass that had been diagnosed as a refractory lung abscess became enlarged and a repeat biopsy resulted in a diagnosis of diffuse large B-cell lymphoma. The patient succumbed to sudden respiratory failure, and the final diagnosis of PPL was confirmed at autopsy. PPL is a rare disease that accounts for 0.45% of all pulmonary malignant tumors and is difficult to diagnose in inoperable cases. Therefore, patients with PPL who do not undergo surgery can be misdiagnosed and consequently treated inappropriately. PPL should therefore be considered in the differential diagnosis of a refractory lung abscess.

f1-ol-09-04-1575: (A) Chest X-ray film on first admission showing a large mass in the right lower lung field. (B and C) Non-enhanced computed tomography scan of the chest on first admission showing a large cavitated mass in the right lower lobe and pleural effusion with multiple gas bubbles.

Mentions:
Upon physical examination, diminished lower right lung sounds were heard. A chest radiograph showed a large mass with multiple air-fluid levels and pleural effusion in the right lower field (Fig. 1A). Chest computed tomography (CT) showed a large mass with a cavity and fluid in the right lower lung lobe, and pleural effusion with multiple gas bubbles (Fig. 1B and C). Laboratory studies revealed a normal white blood cell count of 7,200/mm3, a marginal increase in neutrophils (75%; normal range, 37–72%), an increased C-reactive protein level of 3.4 mg/dl (<0.3 mg/dl) and a normal lactate dehydrogenase level of 150 U/l. Aspirated pleural fluid appeared gray-white and sludgy, with an increased lactate dehydrogenase level of 10,630 U/l (normal range, <200 U/l) and a decreased glucose concentration of 16 mg/dl (normal range, >60 mg/dl). A cell count could not be performed, as the cells had disintegrated.

f1-ol-09-04-1575: (A) Chest X-ray film on first admission showing a large mass in the right lower lung field. (B and C) Non-enhanced computed tomography scan of the chest on first admission showing a large cavitated mass in the right lower lobe and pleural effusion with multiple gas bubbles.

Mentions:
Upon physical examination, diminished lower right lung sounds were heard. A chest radiograph showed a large mass with multiple air-fluid levels and pleural effusion in the right lower field (Fig. 1A). Chest computed tomography (CT) showed a large mass with a cavity and fluid in the right lower lung lobe, and pleural effusion with multiple gas bubbles (Fig. 1B and C). Laboratory studies revealed a normal white blood cell count of 7,200/mm3, a marginal increase in neutrophils (75%; normal range, 37–72%), an increased C-reactive protein level of 3.4 mg/dl (<0.3 mg/dl) and a normal lactate dehydrogenase level of 150 U/l. Aspirated pleural fluid appeared gray-white and sludgy, with an increased lactate dehydrogenase level of 10,630 U/l (normal range, <200 U/l) and a decreased glucose concentration of 16 mg/dl (normal range, >60 mg/dl). A cell count could not be performed, as the cells had disintegrated.

Bottom Line:
The lesion was considered inoperable due to the poor general condition of the patient.PPL is a rare disease that accounts for 0.45% of all pulmonary malignant tumors and is difficult to diagnose in inoperable cases.Therefore, patients with PPL who do not undergo surgery can be misdiagnosed and consequently treated inappropriately.

The current study presents a case of primary pulmonary lymphoma (PPL) mimicking refractory lung abscess that was diagnosed at autopsy. An 80-year-old male with clinically inapparent aspiration presented with a large cavitated mass and pleural effusion. A lung abscess and empyema was diagnosed, therefore, antibiotics were administered and the pleural effusion was drained. Various examinations, including a biopsy, yielded no specific diagnosis. The lesion was considered inoperable due to the poor general condition of the patient. Subsequently, the mass that had been diagnosed as a refractory lung abscess became enlarged and a repeat biopsy resulted in a diagnosis of diffuse large B-cell lymphoma. The patient succumbed to sudden respiratory failure, and the final diagnosis of PPL was confirmed at autopsy. PPL is a rare disease that accounts for 0.45% of all pulmonary malignant tumors and is difficult to diagnose in inoperable cases. Therefore, patients with PPL who do not undergo surgery can be misdiagnosed and consequently treated inappropriately. PPL should therefore be considered in the differential diagnosis of a refractory lung abscess.